I know, I know: you probably weren’t really holding out for a real-life Jurassic Park, in which scientists would use million-year old DNA to clone new full-size dinosaurs. Maybe you were just daydreaming, every once in a while, about visiting such a park and then surviving a dino rampage.

Well, science has destroyed those dreams. Again. Researchers working with fossils from New Zealand have found that DNA has a half-life of 521 years, meaning that just over five centuries is long enough to render strands of DNA relatively useless, at least for the purposes of cloning killer theme part attractions.

Nature reports that paleontologists at the University of Copenhagen and Murdoch University in Perth, Australia “examined 158 DNA-containing leg bones belonging to three species of extinct giant birds called moa.”

The bones ranged in age from 600 to 8,000 years old, and were all from nearly identical preservation conditions. Comparing DNA samples from the various bones, the 521-year half-life was determined. The prediction is that even in the most ideal environment for preservation, all the nucleotide bonds in DNA would break down after 6.8 million years at most. In fact, the data in DNA would essentially be “unreadable” much earlier, perhaps only at 1.5 million years old.

The short version: DNA from real dinosaurs would be far too degraded to use for any engineering purpose. Which anyone probably would have guessed, but confirmation just pours a little salt in the wound. With the most recent dinosaurs dying out around 65 million years ago, that means any budding Jurassic Park designers have to rely on animatronics. So boring. [via Gizmodo]